Historically, Mattacola says, attention paid to jockeys has been secondary to the equine athlete. | Photo: iStock

It’s the fifth race on a beautiful, sunny day at Keeneland Race Course, in Lexington, Kentucky, and the jockeys are waiting in the gate on their mounts. The bell rings and the horses spring forward, looking for the perfect spot from which to make their charge. At the second turn, the No. 8 horse stumbles and recovers, but its jockey tumbles to the dirt. He sits for a few seconds, dazed, but then leaps to his feet and scrambles to safety.

Barely topping the 100-pound mark, jockeys seem undermatched when paired with a 1,000-pound Thoroughbred. In fact, during a recent interview, one jockey lists a jaw-dropping succession of injuries: two broken collarbones, a fractured wrist, broken ribs, a fractured spine and several occasions when he “got his bell rung.” These athletes get back to their job as quickly as possible—and potentially before they’ 100 percent. That’s because, unlike in some other professional sports which offer guaranteed contracts to their players, horse racing operates on a “pay-to-play” model: Jockeys don’t get paid unless they’e riding.

While broken bones are near impossible to miss, concussions are a subtle but potentially more dangerous injury. Concussions—a brain injury caused by whiplash or other blow to the head—are notoriously difficult to diagnose, and symptoms are transient but can last several days or even weeks